Hermetic cable adapter

ABSTRACT

A hermetic adapter includes an adapter body, a hermetic seal disposed between the adapter body and a pin, a contact connected to the pin which is disposed within a dielectric, the dielectric being disposed within the adapter body. A sealing ring is press-fit into the adapter body and includes a sharp edge configured to deform a surface of an external adapter to which the hermetic adapter is attachable.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of U.S. Provisional Application No.61/594,844, filed Feb. 3, 2012, which is hereby incorporated byreference in its entirety.

BACKGROUND

Hermetically sealed cables have been proposed for use in challengingenvironments in order to prevent intrusion of undesirable foreignmatter, gasses, and/or liquids into a cable's interior or into anenclosure to which a cable connects. Such intrusion, if not prevented,may cause premature degradation or failure of a cable or componentswithin an enclosure.

Conventional hermetically sealed cables typically include a connectorpermanently attached at either end of a cable having an outer sealedsheath enclosing one or more inner conductors. The end connectors aretypically permanently attached to the cable by known hermetic sealingmethods. However, such conventional cables require that the cable'sfunction as a hermetically sealed cable be known at the time ofmanufacture. As a result, such conventional cables are typicallymanufactured to order, increasing manufacturing costs and limitingavailability.

SUMMARY

This invention relates to hermetic adapters for applying a hermetic sealto an end of a cable and/or an enclosure-to-cable interface.

In general, in one aspect, the invention features a hermetic adapterwhich includes an adapter body including a sealing element cavity, adielectric cavity and a sealing ring cavity, a pin having an outsidesurface, and a sealing element disposed between the outside surface ofthe pin and the sealing element cavity of the adapter body, the sealingelement and the pin having substantially corresponding thermal expansionproperties such that hermetic seals between the adapter body and thesealing element and between the sealing element and the pin areachievable. The hermetic adapter further includes a dielectric disposedat least partially within the dielectric cavity of the adapter body, thedielectric including a contact cavity, a contact disposed at leastpartially within the contact cavity of the dielectric, the contactforming an electrical connection with the pin and having an attachmentopposite the electrical connection with the pin for attaching to anexternal adapter. The hermetic adapter further includes a sealing ringdisposed at least partially within the sealing ring cavity of theadapter body, the sealing ring including a raised outer surface on anouter surface thereof configured to provide a press fit between thesealing ring and the sealing ring cavity of the adapter body to providea hermetic seal between the sealing ring and the adapter body, and thesealing ring further including a sharp edge configured to deform asurface of the external adapter to provide a hermetic seal between theexternal adapter and the sealing ring.

Implementations of the invention may include one or more of thefollowing features. The sealing ring may contact the dielectric. Thedielectric may be deformed by the sealing ring. The dielectric may bedisposed between and contact both sealing ring and the adapter body.

The adapter body may include female threading at a cable end thereof andincludes male threading at an opposite end thereof opposite the cableend, the sealing element being nearer the opposite end than the cableend and the female threading may have a diameter that is larger than adiameter of the male threading or the female threading and the malethreading may have diameters that are substantially similar.

The contact may include a female socket configured to conductivelyengage the pin. The contact may also include a female socket configuredto conductively engage a conductor of a cable. The contact may have anouter surface with a barb thereon which deforms and engages thedielectric. The barb of the contact may include a barb surfacesubstantially perpendicular to an axis of the contact, the barb surfacefacing away from the sealing element.

The hermetic adapter may further comprise a pin cap conductivelyattached to the pin opposite the contact.

The sealing ring may have a cable end surface, an opposite end surfaceopposite the cable end surface, the outer surface of the sealing ringmay lie between the cable end surface and the opposite end surfacethereof, and the raised outer surface of the sealing ring may beprovided about less than all of the outer surface of the sealing ring.The raised outer surface of the sealing ring may also be provided aboutthe outer surface nearer the cable end surface thereof than the oppositeend surface thereof.

The sealing element may comprise a glass material and may be firstinstalled between the adapter body and the pin in a molten state and maysolidify to form the sealing element.

In general, in another aspect, the invention features a hermeticallysealed cable assembly including a cable, a first cable adapter attachedto a first end of the cable, a second cable adapter attached to a secondend of the cable, a first hermetic adapter engaging the first cableadapter as an external adapter and a second hermetic adapter engagingthe second cable adapter as an external adapter, such that an interiorof the cable is hermetically sealed between the first hermetic adapterand the second hermetic adapter.

BRIEF DESCRIPTION OF THE DRAWINGS

The above mentioned and other aspects, features and advantages can bemore readily understood from the following detailed description withreference to the accompanying drawings, wherein:

FIG. 1 is a cross sectional view of a hermetic adapter and cable adapteraccording to an exemplary embodiment of the present invention;

FIG. 2 is a cross sectional view of a hermetic adapter according toanother exemplary embodiment of the present invention;

FIGS. 3A, 3B, 3C and 3D are left side, front side cross sectional, rightside and front side views of a contact according to another exemplaryembodiment of the present invention;

FIG. 3E is a front side cross sectional view of a contact aftercompression according to another exemplary embodiment of the presentinvention;

FIGS. 4A and 4B are left side and front side cross sectional views of adielectric according to another exemplary embodiment of the presentinvention;

FIG. 5 is a front side cross sectional view of a sealing ring accordingto another exemplary embodiment of the present invention;

FIG. 6 is a cross sectional view of a hermetic adapter and cable adapteraccording to another exemplary embodiment of the present invention;

FIGS. 7A, 7B, 7C and 7D are left side, front side cross sectional, rightside and front side views of a contact according to another exemplaryembodiment of the present invention;

FIG. 7E is a front side cross sectional view of a contact aftercompression according to another exemplary embodiment of the presentinvention;

FIG. 8 is a front side cross sectional view of a dielectric according toanother exemplary embodiment of the present invention;

FIG. 9 is a cross sectional view of a hermetic adapter according toanother exemplary embodiment of the present invention;

FIG. 10 is a front side cross sectional view of a sealing ring accordingto another exemplary embodiment of the present invention;

FIG. 11 is a cross sectional view of a hermetic adapter, cable adapterand cable according to another exemplary embodiment of the presentinvention; and

FIG. 12 is a notional view of a cable assembly according to anotherexemplary embodiment of the present invention.

DETAILED DESCRIPTION

Cable adapters and connectors are described herein, with reference toexamples and exemplary embodiments. Specific terminology is employed indescribing examples and exemplary embodiments. However, the disclosureof this patent specification is not intended to be limited to thespecific terminology so selected and it is to be understood that eachspecific element includes all technical equivalents that operate in asimilar manner. Similarly, while some examples discussed herein concerncoaxial cables, adapters and connectors, the present disclosure alsorelates to cables, adapters and connectors which are not coaxial, suchas, for example, multi-conductor cables, adapters and connectors.

In an exemplary embodiment, shown in FIG. 1, a hermetic adapter 10 isshown adjacent a cable adapter 12. The hermetic adapter 10 is providedwith a cable end 14 and a connector end 16. The cable adapter 12 may befixed to a cable, as will be described in more detail below. Thehermetic adapter 10 connects to the cable adapter 12 or anotherconnector at the cable end 14 and provides a connection to an externalconnector at connector end 16. The external connector may be anothercable adapter, an inlet to a device enclosure, another adapter, etc.

An example of a cable 200 and cable adapter 12 is shown in FIG. 11. Asshown, a cable may include an inner conductor 202, a dielectric 204, ashield 206 and a jacket 208. Any compatible means, of which there aremany known in the art, may be employed to secure the cable and itsconstituent components to the cable adapter 12. As an example, theshield 206 may be soldered or crimped within the cable adapter 12. Inaddition, one or more strain relief components 210 may be provided overthe jacket 208 and optionally over the cable adapter 112 and adapterbody 118.

In the examples shown in FIGS. 1 and 2, the hermetic adapter 10 includesseveral components, including adapter body 18, sealing ring 20,dielectric 22, contact 24, pin 26, sealing element 28 and pin cap 30.The adapter body 18 may be provided with a female thread 32, a malethread 34, a sealing ring cavity 36, a dielectric cavity 38 and a sealcavity 40. An example of an adapter body 18, sealing element 28 and pinare shown in greater detail in FIG. 2. In one example, the sealingelement 28 may be formed of thermal expansion matching glass, such asCorning 7070 Lithia Potash Borosilicate Glass or an equivalent. In oneexample, the pin 26 may be formed of a metal alloy configured to becompatible with the thermal expansion characteristics of the sealingelement 28. In one example, the pin 26 may be formed of a nickel-cobaltferrous alloy such as KOVAR (a trademark of Carpenter TechnologyCorporation). In one example, the adapter subassembly shown in FIG. 2may be assembled by aligning the pin 26 to the adapter body 18 andintroducing molten glass into a mold having a cavity configured to formthe sealing element 28 in the position desired once the molten glass issolidified. Thus, the alignment between the pin 26 and the adapter bodymay be fixed by the sealing element 28 as the sealing element 28hardens. Once the sealing element 28 is solidified, a hermetic seal isformed between the adapter body 18 and the sealing element 28 andbetween the seal and the pin 26.

An example of a contact 24 is shown in FIGS. 3A-3E. Contact 24 mayinclude two female connector ends, a pin end 42 and a cable end 44. Thefemale connector ends may be configured to attach to male pins orconductors of the same or different diameters or shapes. For example, asshown in FIGS. 1 and 3A-3E, contact 24 may be configured to connect atits pin end 42 to a pin 26 having a smaller diameter than a cableconductor (not shown) to which the contact 24 is configured to attach atits cable end 44. The female ends 42 and 44 of the contact 24 may beprovided with one or more slots configured to provide a desiredinsertion or withdrawal force to or from the male pin or cable conductorto which they are configured to attach. Slots may also be configured toimprove an electrical connection between the contact 24 and a pin orcable conductor. The contact 24 may be inserted into an inner bore 48 ofthe dielectric 22. An example of a dielectric 22 is shown in greaterdetail in FIGS. 4A and 4B. The contact 24 may be provided with one ormore lips 50 configured to engage surfaces of the dielectric 22 tomechanically hold the contact 24 and dielectric 22 together. Duringassembly, the dielectric is slightly deformed as the contact 24 isforcibly inserted through the inner bore 48 of the dielectric 22 untilthe lips 50 of the contact 24 engage the appropriate surfaces of thedielectric. The dielectric may be provided within the dielectric cavity38 of the adapter body 18.

An example of a sealing ring 20 is shown in FIG. 5. Sealing ring 20 mayinclude a sharp edge 52 and an outer raised surface 54. As shown in FIG.1, the sharp edge 52 of the sealing ring may be oriented towards thecable end 14 of the hermetic adapter 10 when the sealing ring 20 isinserted into the adapter body 18. The sharp edge 52 is configured todeform a cable adapter 12 or other connector to which the hermeticadapter is attached, digging a trough into the attached adapter 12 orconnector. In a preferred embodiment, a material of the sealing ring 20is harder than a material of the cable adapter 12. In one example, thesurfaces of the sharp edge 52 form an included angle 56 of substantially90° when viewed in cross section. Other included angles 56 are alsopossible. The deformation of the adapter 12 or connector, combined withthe forcible insertion of the sharp edge 52 into the trough therebycreated form a hermetic seal between the sealing ring 20 and theattached adapter 12 or connector. The outer raised surface 54 of thesealing ring 20 may be provided anywhere along the outer surface of thesealing ring 20. In the example shown in FIG. 5, the outer raisedsurface 54 is provided at an end of the sealing ring towards the sharpedge 52. The outer raised surface 54 of the sealing ring has a slightlylarger diameter than a diameter of the sealing ring cavity 36 into whichthe sealing ring 20 is installed, resulting in a press-fit between thesealing ring and the adapter body 18. In one example, the sealing ring20 may be installed into the adapter body 18 as far as it will go untila surface of the sealing ring 20 opposite the sharp edge 52 bottoms outagainst an adjacent surface of the sealing ring cavity 36 of the adapterbody 18. Thus, the sealing ring 20 and the adapter body 18 may bepress-fit together during assembly, forming a hermetic heal between thesealing ring 20 and the adapter body 18. When the outer raised surface54 is provided towards the sharp edge 52 along the outer surface of thesealing ring 20, the hermetic seal between the adapter 12 and connectorand the hermetic seal between the sealing ring 20 and the adapter body18 are thus advantageously brought close to one another, possiblylessening the chance of thermal or other environmental effects causing afailure or reduction in effectiveness of either hermetic seal.

As shown in FIG. 1, the sealing ring 20 may be provided with an innerbore 58 having a smaller diameter than the outer surface of thedielectric 22. Thus, when the sealing ring is press-fit into the adapterbody 18, the dielectric (and the contact 24 held therein) may bemechanically confined within the adapter body 18, as shown in FIG. 1.

The pin cap 30 may be attached to the pin 26 in any number of ways. Forexample, the pin cap 30 may be press-fit onto the pin 26 or the pin cap30 may be soldered onto the pin 26.

In another embodiment, shown in FIG. 6, a hermetic adapter 100 mayinclude an adapter body 118, sealing ring 120, dielectric 122, contact124, pin 126, seal 128 and pin cap 130. The adapter body 118, seal 128and pin 126 may be assembled as described above with respect to FIG. 1.An example of an assembled subassembly including an adapter body 118, aseal 128 and a pin 126 is shown in FIG. 9.

In the example shown in FIG. 6, dielectric 122 is inserted into an innerbore of the contact 124. An example of a contact 124 is shown in greaterdetail in FIGS. 7A-7E, and an example of a dielectric 122 is shown ingreater detail in FIG. 8. The contact 124 may include a barb 132extending from an outer surface thereof. The barb 132 may be formed withan angled surface 133 facing a dielectric insertion direction 134 and aflat surface 136 adjacent the angled surface 133, defining a sharp edge138 at the outermost portion of the barb 132. As shown in FIG. 6, adiameter of the sharp edge 138 of the barb 132 may be configuredslightly larger than an inner bore 140 of the dielectric 122 shown inFIG. 8 so that the barb 132 digs into the dielectric 122 once thecontact 124 and the dielectric 122 are assembled together. Thus, thecontact 124 may be held captively within the dielectric 122.

An example of a sealing ring 120 is shown in greater detail in FIG. 10.As in the example of sealing ring 20, shown in FIG. 5, sealing ring 120may include a sharp edge 144 and a raised outer surface 146. Similarly,as with the example shown in FIG. 1, the sealing ring 120 may form ahermetic seal against an adjacent adapter 112 or connector by the sharpedge digging a trough into the adapter 112 or connector, and a hermeticseal may be formed between the raised outer portion 146 of the sealingring 120 and the adapter body by virtue of a press-fit between theadapter body 118 and the sealing ring 120. In contrast to the exampleshown in FIG. 1, though, sealing ring 120 may comprise two or moresurfaces opposite the end surface thereof containing the sharp edge 144.For example, as shown in FIG. 10, sealing ring 120 includes surfaces 148and 150 which oppose the surface containing sharp edge 144. As shown inFIG. 6, the opposing surface 150 furthest from the sharp edge 144 maydefine a bottoming out point during assembly between the sealing ring120 and the adapter body 118. A gap 152 may exist between intermediateopposing surface 148 and an adjacent surface of the adapter body 118. Inone example, shown in FIG. 6, a length 154 of an outer surface of thedielectric 122 measured along the main axis of the dielectric 122 may beconfigured slightly larger than a corresponding depth of the dielectriccavity 142 of the adapter body 118 so that when the sealing ring 120 isinserted until its end surface 150 bottoms out against the adapter body118, dielectric 122 contacts the sealing ring 120 and is slightlydeformed or compressed as the sealing ring 120 is fully inserted. Inother examples, the length 154 of the dielectric 122 or thecorresponding depth of the dielectric 122 cavity 142 are configured sothat no deformation or compression of the dielectric 122 occurs duringinsertion of the sealing ring 120 into the adapter body 118.

Materials for the various components may be chosen from among a widerange of suitable materials. In one example, adapter body 18 or 118 maybe formed of passivated stainless steel, sealing ring may be formed ofpassivated stainless steel, contact 24 or 124 and pin cap 30 or 130 maybe formed of gold plated beryllium-copper, dielectric 20 or 120 may beformed of PTFE (polytetrafluoroethylene, a brand of which is Teflon).Materials for the pin 26 or 126 and the sealing element 28 or 128 arediscussed above.

In an aspect of the present disclosure, female threads (such as 32 or156) and male threads (such as 34 or 158) of an adapter body 18 or 118may be configured similarly or differently. For example, in the exampleshown in FIG. 2, male threads 34 and female threads 32 are differentlyconfigured. As one particular example, male threads 34 may be defined as¼″-36, while female threads 32 may be defined as 5/16″-40. As anotherexample, shown in FIG. 9, male threads 158 and female threads 156 mayboth be defined as 7/16″-28. In this example, a hermetic adapter 100,shown in FIG. 6, may be attached to a cable adapter 112 and otheradapters may be attached at connector end 16 of the hermetic adapter 100without concern for matching thread definitions. In other words, malethreads 158 would have the same thread definition as the male threads ofthe cable adapter 112, and any connector originally intended for theattachment to the cable adapter 112 would also be configured to attachto the hermetic adapter 100.

In another aspect of the present disclosure, the dielectric 22 or 122 iscaptured (if not deformed or compressed into position) in the hermeticadapter 10 or 100 by a mechanical feature. For example, the dielectric22 or 122 may be held against the adapter body 18 or 118 by an endsurface of a sealing ring 20 or 120. In environments with largetemperature or pressure swings, such mechanical capturing ensures thatthe dielectrics (which may be formed of a plastic such as PTFE) stay inplace no matter the environment into which the adapter is placed, aparticular concern of adapters of the type described herein.

In yet another aspect of the present disclosure, shown in FIG. 12,hermetic adapters 10 or 100 may be attached to one or more cableadapters 12 or 112, which may be attached to one or both ends of a cable200 to render the cable assembly hermetically sealed. Thus, anyconventional cable may be rendered hermetically sealed simply byattaching hermetic adapters 10 or 100 of the type disclosed herein toboth ends thereof.

In addition, the embodiments and examples above are illustrative, andmany variations can be introduced on them without departing from thespirit of the disclosure or from the scope of the appended claims. Forexample, elements and/or features of different illustrative andexemplary embodiments herein may be combined with each other and/orsubstituted for each other within the scope of this disclosure. Asanother example, two or more of the various components described hereinmay be combined into one or more consolidated components, or one of thevarious single components described herein may be provided as two ormore sub-components.

What is claimed is:
 1. A hermetic adapter comprising: an adapter bodyincluding a sealing element cavity, a dielectric cavity and a sealingring cavity; a pin having an outside surface; a sealing element disposedbetween the outside surface of the pin and the sealing element cavity ofthe adapter body, the sealing element and the pin having substantiallycorresponding thermal expansion properties such that hermetic sealsbetween the adapter body and the sealing element and between the sealingelement and the pin are achievable; a dielectric disposed at leastpartially within the dielectric cavity of the adapter body, thedielectric including a contact cavity; a contact disposed at leastpartially within the contact cavity of the dielectric, the contactforming an electrical connection with the pin and having an attachmentopposite the electrical connection with the pin for attaching to anexternal adapter; and a sealing ring disposed at least partially withinthe sealing ring cavity of the adapter body, the sealing ring includinga raised outer surface on an outer surface thereof configured to providea press fit between the sealing ring and the sealing ring cavity of theadapter body to provide a hermetic seal between the sealing ring and theadapter body, and the sealing ring further including a sharp edgeconfigured to deform a surface of the external adapter to provide ahermetic seal between the external adapter and the sealing ring.
 2. Thehermetic adapter of claim 1, wherein the sealing ring contacts thedielectric.
 3. The hermetic adapter of claim 2, wherein the dielectricis compressed by the sealing ring.
 4. The hermetic seal of claim 2,wherein the dielectric is disposed between and contacts both the sealingring and the adapter body.
 5. The hermetic adapter of claim 1, whereinthe adapter body includes female threading at a cable end thereof andincludes male threading at an opposite end thereof opposite the cableend, the sealing element being nearer the opposite end than the cableend.
 6. The hermetic adapter of claim 5, wherein the female threadinghas a diameter that is larger than a diameter of the male threading. 7.The hermetic adapter of claim 5, wherein the female threading and themale threading have diameters that are substantially similar.
 8. Thehermetic adapter of claim 1, wherein the contact includes a femalesocket configured to conductively engage the pin.
 9. The hermeticadapter of claim 1, wherein the contact includes a female socketconfigured to conductively engage a conductor of a cable.
 10. Thehermetic adapter of claim 1, wherein the contact has an outer surfacewith a barb thereon which deforms and engages the dielectric.
 11. Thehermetic adapter of claim 1, wherein the barb of the contact includes abarb surface substantially perpendicular to an axis of the contact, thebarb surface facing away from the sealing element.
 12. The hermeticadapter of claim 1, further comprising a pin cap conductively attachedto the pin opposite the contact.
 13. The hermetic adapter of claim 1,wherein the sealing ring has a cable end surface, an opposite endsurface opposite the cable end surface, the outer surface of the sealingring lying between the cable end surface and the opposite end surfacethereof, and the raised outer surface of the sealing ring is providedabout less than all of the outer surface of the sealing ring.
 14. Thehermetic adapter of claim 13, wherein the raised outer surface of thesealing ring is provided about the outer surface nearer the cable endsurface thereof than the opposite end surface thereof.
 15. The hermeticadapter of claim 1 wherein the sealing element comprises a glassmaterial first installed between the adapter body and the pin in amolten state and which solidifies to form the sealing element.
 16. Ahermetically sealed cable assembly comprising: a cable; a first cableadapter attached to a first end of the cable; a second cable adapterattached to a second end of the cable; a first hermetic adapteraccording to claim 1 engaging the first cable adapter as an externaladapter; and a second hermetic adapter according to claim 1 engaging thesecond cable adapter as an external adapter, wherein an interior of thecable is hermetically sealed between the first hermetic adapter and thesecond hermetic adapter.